Steel steam and flame

There was a string of lamps in the tunnel, but Cassia did not turn it on. The nearly three-meter-wide tunnel was flexible enough for Cassia to cope in the dark. Cassia's sense of direction has become Cassia's most sensitive perception at the moment. She always keeps her steps in the middle of the tunnel. Every time she deviates from the direction, Cassia will completely write it down in her head so that when the detection is completed, she can draw a route map that is not much different from the actual one. Come.

Connected to the air circulation system, the sonic pulses detected some air delivery lines. It was not turned on at the moment, and the tunnel seemed a bit dull. If biological poisons are used here... While running, Cassia suddenly thought that if mixed into the air, it would definitely have a huge effect when the enemy is unprepared.

I don’t doubt that others didn’t think of this when the air circulation system was first built. He didn't say it clearly, maybe he was still wary of his protectors. Information can be leaked to the transportation team, and they are also high-level people within the organization. Driven by interests and in today's era, it seems that anything can happen.

The tunnel generally presents a straight line, but the angle of the curve is very large. If the sensitivity of perception is slightly lower, the change may not be felt. And in the middle of the tunnel, Cassia also found a fork in the road. The other routes were, of course, dead ends and were equipped with many sensing devices, sonic pulses picking up their outlines. When it reaches the cavity at the bottom of the route, the movement route of the minecart-like mobile tool is more or less prescribed by the analysis machine.

I don’t know if these forked roads are used to prevent enemies, or are used to test warehouse management and protectors like myself. From the words of Adolf and No. 5 who have left, it is easy to guess that such a task is probably a process used to add reasons and certainty for promotion to some elites. Just like when you have the opportunity, even if you just help pass a cup and other tools, you can still put your name at the end of some important research results.

In less than four minutes, an underground semicircular cavity with an area of ​​nearly a hundred square meters completely revealed its shape and appeared in Cassia's perception. After a few breaths, Cassia, who was standing at the entrance of the cave, made sure that there was no redundant detection equipment around, and then entered the cavity.

For the size of a three-story building, the track in the tunnel suddenly cuts off when it reaches the center of the cavity. There is nothing around except air. On the side, just as No. 5 said, several fixed beams of an elevator penetrate the cavity from top to bottom. Two alloy safety doors cut them off, leaving only the empty space. The cavity comes in one section included.

Cassia walked to the safety doors and looked up and down. Then high-frequency sound waves were emitted, penetrating these safety doors and detecting the top and end of the elevator.

"It reaches nearly one hundred meters upward to the ground, and nearly two hundred meters downward, with three safety doors in between before reaching the bottom." Along the shaft of the elevator, the high-frequency sound beams slowly and consciously focus in one direction. "There is an unloading platform at the bottom of the shaft, as well as a simple push trolley. It is also a cavity structure. A door connects this cavity, and behind the door is..."

Cassia closed her eyes, and her highly concentrated mind seemed to suddenly leave her body at this moment, appearing directly under the shaft and standing in front of the alloy door with its teeth closed. The sound wave frequency suddenly increased by two or three levels at this moment, entering the third stage, and completely self-analyzing the changing structure of the throat. What is the upper limit of high-frequency sound waves? Cassia has not conducted a systematic test until now.

As the sound beam moves, the alloy door is like a layer of transparent air, gradually fading in Cassia's head. A wide underground building immediately appeared "in front of" Cassia. Just a small part, approximately fishbone-like distribution. Most of the many rooms are equipped with equipment and machines for applications. From the weak vibration feedback on them, it can be known that most of the observed machines are operating.

Just not seeing the researchers in the laboratory base for a while, Cassia tried to increase the frequency again, but right in front of him, several glass test tubes placed on the stands suddenly cracked. As if he had been hit hard in the head, Cassia immediately stopped detecting and returned to the cavity as if he had woken up from sleepwalking.

Without any words, Cassia subconsciously lowered her heartbeat and breathing, turned around and escaped into the tunnel along the original route. Three and a half minutes later, Cassia, whose expression remained unchanged, returned to the basement warehouse again. There was no one around. Upstairs, the other three people were doing their own things in their rooms, unaware of what was happening here at this moment.

Nothing happened, with this mood, Cassia slowly went back to her room and sat on the bed. After a while, about half an hour, there was no contact sound from the communicator in the ears, and Cassia breathed out heavily: "We have to find opportunities and time to study the high-frequency sound waves in the third stage. changes and applications.”

,,,,,,

"Did you get the records?"

"The assistant went to print and will be here soon." Shortly after the reply came, there was a knock on the door. After saying "come in", the door was opened, and a thin man with glasses stood at the door. He walked in with a three-finger-thick piece of paper in his hand and placed it on the table in front of the three people in the room.

"Here are all the surveillance records, all converted into pictures, recorded every five seconds. I selected the time period within five minutes before and after." There was no fluctuation in the tone of the words of the thin man, like a simple and The cheap repeater repeated a boring tune, "I discovered this in the past tense, Professor Mosier."

The skinny man said as he pulled out two pieces of printing paper from the bottom of the stack of papers. The warmth had not yet been lost, the ink seemed not to have dried, and the smell spread throughout the room in an instant.

"Several rooms there are shock chambers, and an ultrasonic record of varying frequencies suddenly appeared on the monitor in each room. The record in the room where the test tubes were broken was the highest."

But Professor Mosier said "Oh", took the record sheet from the skinny man's hand, and asked: "In terms of time, the two should completely overlap, right?"

The skinny man nodded, "It completely coincides. The machine we use has been checked and there is no fault. I have also read the records in the analysis machine. Since yesterday, there are no records of calling and opening. It is very certain that the test tube is broken. The reason is that a sudden high-frequency sound wave will shatter it, but the source of this sound wave is..."

"I understand." But Professor Mosier nodded, "Let's go to that room and take a look again."